Cell membrane are made of

Options

A. Phospholipids and proteins
B. Pectin
C. Cellulose
D. Lipid and hemicellulose

Answer

### Step-by-Step Solution:

1. **Understanding the Cell Membrane**: The cell membrane, also known as the plasma membrane, is the outermost layer of an animal cell. It serves as a protective barrier between the cell's internal environment and the external environment.

2. **Composition of the Cell Membrane**: The primary components of the cell membrane are phospholipids and proteins. The phospholipids form a bilayer, which is essential for the membrane's structure and function.

3. **Role of Phospholipids**: Phospholipids have hydrophilic (water-attracting) heads and hydrophobic (water-repelling) tails. This unique structure allows them to arrange themselves into a bilayer, which is crucial for forming the semi-permeable nature of the membrane.

4. **Inclusion of Proteins**: The cell membrane also contains various proteins, including integral proteins that span the membrane and peripheral proteins that are attached to the surface. These proteins play vital roles in transport, signaling, and maintaining the structure of the membrane.

5. **Functionality of the Cell Membrane**: The cell membrane is semi-permeable, meaning it selectively allows certain molecules to pass through while blocking others. This selectivity is essential for maintaining homeostasis within the cell.

6. **Conclusion**: Therefore, the cell membrane is primarily made up of phospholipids and proteins, making option one the correct answer.